diff --git a/base/modules/cutil.c b/base/modules/cutil.c
index 13b7e1e9..503e14a5 100644
--- a/base/modules/cutil.c
+++ b/base/modules/cutil.c
@@ -1,29 +1,9 @@
 #include <sys/time.h>
 #include <stdio.h>
 #include <string.h>
-#include "psb_internals.h"
 
-#ifdef LowerUnderscore
-#define psi_c_diffadd   psi_c_diffadd_
-#endif
-#ifdef LowerDoubleUnderscore
-#define psi_c_diffadd   psi_c_diffadd__
-#endif
-#ifdef LowerCase
-#define psi_c_diffadd   psi_c_diffadd
-#endif
-#ifdef UpperUnderscore
-#define psi_c_diffadd   PSI_C_DIFFADD_
-#endif
-#ifdef UpperDoubleUnderscore 
-#define psi_c_diffadd   PSI_C_DIFFADD__
-#endif
-#ifdef UpperCase
-#define psi_c_diffadd   PSI_C_DIFFADD
-#endif
-
-void psi_c_diffadd(char *p1, char *p2, int *ret)
+void psi_c_diffadd(void *p1, void *p2, int *ret)
 {
-  *ret = (int)(p2-p1);
+  *ret = (int)((char *)p2-(char *)p1);
   return;
 }
diff --git a/base/modules/penv/psi_penv_mod.F90 b/base/modules/penv/psi_penv_mod.F90
index 6a5dd7aa..2e880367 100644
--- a/base/modules/penv/psi_penv_mod.F90
+++ b/base/modules/penv/psi_penv_mod.F90
@@ -696,21 +696,32 @@ contains
 
   subroutine psi_get_sizes()
     use psb_const_mod
-    real(psb_dpk_) :: dv(2) 
-    real(psb_spk_) :: sv(2) 
-    integer(psb_i2pk_):: i2v(2)
-    integer(psb_mpk_) :: mv(2)
-    integer(psb_ipk_) :: iv(2)
-    integer(psb_lpk_) :: lv(2)
-    integer(psb_epk_) :: ev(2)
-
-    call psi_c_diffadd(sv(1),sv(2),psb_sizeof_sp)
-    call psi_c_diffadd(dv(1),dv(2),psb_sizeof_dp)
-    call psi_c_diffadd(i2v(1),i2v(2),psb_sizeof_i2p)
-    call psi_c_diffadd(mv(1),mv(2),psb_sizeof_mp)
-    call psi_c_diffadd(iv(1),iv(2),psb_sizeof_ip)
-    call psi_c_diffadd(lv(1),lv(2),psb_sizeof_lp)
-    call psi_c_diffadd(ev(1),ev(2),psb_sizeof_ep)
+    use iso_c_binding
+    
+    real(psb_dpk_), target     :: dv(2) 
+    real(psb_spk_), target     :: sv(2) 
+    integer(psb_i2pk_), target :: i2v(2)
+    integer(psb_mpk_), target  :: mv(2)
+    integer(psb_ipk_), target  :: iv(2)
+    integer(psb_lpk_), target  :: lv(2)
+    integer(psb_epk_), target  :: ev(2)
+    interface
+      subroutine psi_c_diffadd(p1, p2, val) &
+           & bind(c,name="psi_c_diffadd")
+        use iso_c_binding
+        import :: psb_mpk_
+        type(c_ptr), value :: p1, p2
+        integer(psb_mpk_) :: val
+      end subroutine psi_c_diffadd
+    end interface
+    
+    call psi_c_diffadd(c_loc(sv(1)),c_loc(sv(2)),psb_sizeof_sp)
+    call psi_c_diffadd(c_loc(dv(1)),c_loc(dv(2)),psb_sizeof_dp)
+    call psi_c_diffadd(c_loc(i2v(1)),c_loc(i2v(2)),psb_sizeof_i2p)
+    call psi_c_diffadd(c_loc(mv(1)),c_loc(mv(2)),psb_sizeof_mp)
+    call psi_c_diffadd(c_loc(iv(1)),c_loc(iv(2)),psb_sizeof_ip)
+    call psi_c_diffadd(c_loc(lv(1)),c_loc(lv(2)),psb_sizeof_lp)
+    call psi_c_diffadd(c_loc(ev(1)),c_loc(ev(2)),psb_sizeof_ep)
 
   end subroutine psi_get_sizes
 
diff --git a/base/modules/psb_const_mod.F90 b/base/modules/psb_const_mod.F90
index 5f13edaf..c2277da0 100644
--- a/base/modules/psb_const_mod.F90
+++ b/base/modules/psb_const_mod.F90
@@ -101,24 +101,24 @@ module psb_const_mod
   integer, parameter  :: psb_lpk_ = -1
 #endif
 
-  integer(psb_ipk_), save      :: psb_sizeof_sp
-  integer(psb_ipk_), save      :: psb_sizeof_dp
-  integer(psb_ipk_), save      :: psb_sizeof_i2p = 2
-  integer(psb_ipk_), save      :: psb_sizeof_mp  = 4
-  integer(psb_ipk_), save      :: psb_sizeof_ep  = 8
+  integer(psb_mpk_), save      :: psb_sizeof_sp
+  integer(psb_mpk_), save      :: psb_sizeof_dp
+  integer(psb_mpk_), save      :: psb_sizeof_i2p = 2
+  integer(psb_mpk_), save      :: psb_sizeof_mp  = 4
+  integer(psb_mpk_), save      :: psb_sizeof_ep  = 8
 
 #if defined(IPK4) && defined(LPK4)
-  integer(psb_ipk_), save      :: psb_sizeof_ip = 4
-  integer(psb_ipk_), save      :: psb_sizeof_lp = 4
+  integer(psb_mpk_), save      :: psb_sizeof_ip = 4
+  integer(psb_mpk_), save      :: psb_sizeof_lp = 4
 #elif  defined(IPK4) && defined(LPK8)
-  integer(psb_ipk_), save      :: psb_sizeof_ip = 4
-  integer(psb_ipk_), save      :: psb_sizeof_lp = 8
+  integer(psb_mpk_), save      :: psb_sizeof_ip = 4
+  integer(psb_mpk_), save      :: psb_sizeof_lp = 8
 #elif  defined(IPK8) && defined(LPK8)
-  integer(psb_ipk_), save      :: psb_sizeof_ip = 8
-  integer(psb_ipk_), save      :: psb_sizeof_lp = 8
+  integer(psb_mpk_), save      :: psb_sizeof_ip = 8
+  integer(psb_mpk_), save      :: psb_sizeof_lp = 8
 #else
-  integer(psb_ipk_), save      :: psb_sizeof_ip = -1
-  integer(psb_ipk_), save      :: psb_sizeof_lp = -1
+  integer(psb_mpk_), save      :: psb_sizeof_ip = -1
+  integer(psb_mpk_), save      :: psb_sizeof_lp = -1
 #endif
 
   !